In the sheet industry, various types of plastic foam sheets or composites are often used in various industries such as boating, automotive, airplane, luggage, seating, helmets, construction, acoustical applications, and other custom use applications. For example, in the automotive and airline industries plastic foam sheets having fibrous non-woven batt content have been used for vehicle headliners, interior door panels, and for decorative sound absorbing panels such as shown in U.S. Pat. No. 6,204,209 by Rozek et al. titled “Acoustical Composite Headliner;” U.S. Pat. No. 6,171,419 by Heiman et al. titled “Apparatus And Method For Forming An Interior Panel For A Vehicle;” U.S. Pat. No. 5,827,460 by Brentrup et al. titled “Production Of Fiber Composite;” U.S. Pat. No. 5,804,312 by Noma et al. titled “Processable Sheet With Excellent Rigidity And Process For Producing The Same;” U.S. Pat. No. 5,681,519 by Kelman titled “Method Of Squeeze Molding A Foam Cored Article;” and U.S. Pat. No. 5,536,556 by Juriga titled “Insulating Sheet.” In these examples, the batt material is cotton, fiberglass, synthetic thermoplastic fiber material such as nylon, or a combination of natural and synthetic fibers. The batt material is used as a reinforcement to help the sheet to retain its shape, e.g., rigidity, during molding or to enhance durability in high temperature applications and to enhance sound attenuation or acoustic absorption.
Also, plastic panels or sheets and other materials have been developed from recycled materials over the years. Examples of such recycled products and methods of recycling plastics and other materials can be seen in U.S. Pat. Nos. 5,447,675 and 5,346,171 each by Kehphart and each titled “Method And Apparatus For Forming Plastic Panels From Recycled Plastic Chips;” U.S. Pat. No. 5,589,260 by Ben Zvi et al. titled “Method And Apparatus For Producing Plastic Products;” and U.S. Pat. No. 5,585,122 by Drum et al. titled “Apparatus For Converting Raw Materials Into A Molded End Product.”
Plastic foam sheets, and particularly high strength plastic foam sheets, however, have conventionally had quite a bit of difficulty retaining fasteners such as screws, rivets, threaded eyelets, or hooks. The fasteners are often formed of a metal material and the smooth surfaces between the metal material and the plastic material allows the fastener to slip, slide, or detach from the plastic material.